Studies On The Adaptability Of Huaibei Coal In Texaco Gasification Technology And Technical Economy

Huaibei coal can't be used directly in Texaco Gasification technology for its high ash fusion temperature (FT>1400℃). In order to solve the problem, four Huaibei coals (A,B,C,D) with high fusion temperature and three other low ash fusion temperature coals (L1,L2,L3) were selected in this paper, the qualitative analysis and quantitative analysis are applied to analyze the crystal mineral composition in coal, detected the flux and coal blending on the improvement of Huaibei coal ash fusion temperature, coal ash mineral behavior and fluxing mechanism of flux were researched, water slurry property after adding flux and coal blengding were studied, as well as technical economic of Huaibei coal. The results are as follows:(1) The mineral composition in Huaibei coals generally includes kaolinite, quartz, calcite, gypsum, pyrite and dolomite. The ash fusion temperatures are related to the content of Flux minerals, refractory minerals and total minerals. As the heating temperature increases, the content of quartz, anhydrite and hematite in coal ash decrease in reducing conditions and some new mineral phases are formed. Mullite formed in the heating process is the main reason for ash fusion temperature high of coals.(2) Adding flux can decrease ash fusion temperature, but adding flux alone needs more additives and increases the ash discharge. Compound flux is better than single flux, some new fluxing phases such as cordierite, forsterite, hercynite and fayalite are formed which can decrease the ash fusion temperature by broken the structure of aluminosilicate in Huaibei coals.(3) Coal blending also can decrese ash fusion temperature efficiently, the sequence of efficiency is:L1>L3>L2, If the flux was added less than 3%(coal base,%), the amount of huaibei coals in blending coals will be more than 60%.(4) The concentration of coal water slurry of A and C coals are 70% and 69%, the featuras of coal water slurry such as slurry viscosity, stability, fluidity were almost not influenced significantly by adding flux. The concentration of coal water slurry after blending coal can achieved 68% and 69%, the apparent viscosity are lower than 1500 mPa-s, apparent viscosity can meet the demand of Texaco gasifition.(5) Adding flux changed the content of gas composition, with the oxygen-coal ratios increase, the content of CO, H2 will increase at first and then decrease. The concentration of coal water slurry every raise 1%, the content of coarse coal gas will increase about 1%. Coal consumption, oxygen consumption and total cost are lower than other low ash fusion temperature coal when use Huaibei coals.